磁共振扩散加权成像和血管成像在急性基底动脉尖综合征诊断中的应用

目的 探讨磁共振扩散加权成像(DWI)和磁共振血管成像(MRA)在急性基底动脉尖综合征(top of the basilar syndrome,TOBS)诊断中的临床应用.方法 回顾分析17例急性TOBS患者的DWI及6例MRA影像资料和临床表现.结果 17例TOBS患者共检出67个病灶,DWI呈明显高信号,病变分布于基底节5个、丘脑10个、桥脑13个、中脑7个、颞叶内侧7个、枕叶8个、小脑16个、桥小脑脚1个.6例MRA均见基底动脉和大脑后动脉程度范围不同的形态、信号改变,其中5例基底动脉尖部纤细,1例基底动脉局部血流信号中断并尖部变细.结论 DWI及MRA检查对TOBS的早期诊断和早期溶栓治疗提供有力依据,可作为TOBS的常规检查方法.     

磁共振血管成像结合弥散加权成像在急性脑梗死中的诊疗价值及准确性分析

目的 研究磁共振血管成像（MRA）结合弥散加权成像（DWI）检查应用于急性脑梗死临床诊断中的价值。方法 选择2021年2月至2022年12月本院60例急性脑梗死患者作为研究对象，患者均经DWI检查、MRA检查，分析DWI、MRA单一检查以及联合检查的诊断结果。结果 MRA检查的急性脑梗死检出率为95.0%,DWI检查的疾病检出率为98.3%，两者联合检查的检出率为100%，各项数据相比，差异无统计学意义（P>0.05）。结论 于急性脑梗死患者的临床诊治中，DWI和MRA联合可获较高检出率。     

DWI、MRA在急性脑缺血中的联合诊断价值

目的探讨磁共振弥散加权成像（DWI）与磁共振血管成像（MRA）在急性期脑缺血中的联合诊断价值。方法收集经临床和影像学确诊为急性脑梗死的患者40例,所有患者行常规MRI、FLIAR、DWI及MRA检查。对MRA原始图像进行最大密度投影（MIP）重建,选取病灶中心和健侧相应部位8×8像素大小区域,测定各自的表观扩散系数（ADC）,并计算rADC值。结果 40例患者的DWI图像均显示与临床症状及体征相符的病灶,尤其是在超急性期,病灶具有较高的信号强度和清晰度。MRA检查均获得清晰血管图像,结果显示动脉硬化3例,动脉狭窄或闭塞28例;40例中,24例大面积病灶的血管病变阳性率为100%。DWI显示病灶解剖定位均与MRA上血管异常解剖定位有较好的一致性。结论 DWI对脑梗死超急性期、急性期均有很高的敏感性,MRA对颅内大血管及其部分分支的狭窄或闭塞情况均能很好地显示。通过DWI和MRA联合扫描进行比较,可以对应显示同一区域脑实质和脑血管情况,进一步判定责任血管。     

大脑中动脉狭窄的磁共振血管成像与数字减影血管造影的对照研究

目的 探讨磁共振血管成像(MRA)在大脑中动脉狭窄或闭塞病变中的诊断价值.方法 35例缺血性脑血管病患者先后行MRA及DSA检查,以DSA为金标准,分析MRA对不同程度大脑中动脉狭窄的诊断价值.结果 35例患者70支大脑中动脉中,MRA显示正常血管28支,病变血管42支,病变部位47处,MRA与DSA诊断符合53处,符...     

磁共振成像-T2液体衰减反转恢复序列成像高信号血管征在急性大脑中动脉梗死患者诊断中的临床应用

目的探讨磁共振T2液体衰减反转恢复序列(FLAIR)高信号血管征象(HVS)对于急性大脑中动脉区脑梗死的早期诊断的临床价值。方法回顾性分析2013年8月至2015年8月上海交通大学医学院附属苏州九龙医院神经内科住院的91例急性大脑中动脉脑梗死患者,所有患者均在24 h内进行完整磁共振成像(MRI)检查[包括FLAIR、磁共振弥散加权成像(DWI)及磁共振血管成像(MRA)]及CT血管造影(CTA)检查,观察大脑中动脉狭窄或闭塞的情况。结果 91例患者大脑中动脉从轻中度狭窄、重度狭窄到闭塞,HVS阳性所占比例分别为1/16(6%)、7/18(38%)、36/57(63%);对比重度狭窄组与轻中度狭窄组,差异有统计学意义(P=0.025),对比闭塞组与轻中度狭窄组,差异有统计学意义(P<0.01)。结论在大脑中动脉重度狭窄或闭塞的患者中T2-FLAIR序列HVS阳性率高,HVS对于急性大脑中动脉区脑梗死的早期临床诊断有重要意义。     

3.0T MR多技术联合应用在头颈部动脉血管狭窄病变中的诊断价值

目的:分析3.0T MR 3D TOF MRA、高分辨CE MRA、双反转恢复颈动脉血管壁黑血成像在头颈部动脉血管狭窄病变检查中的技术特点,探讨其联合应用在头颈部动脉血管狭窄病变中的诊断价值。方法:研究所用技术经医院伦理委员会审查批准,向患者认真介绍后由患者签字同意。选择2009年5月~2009年6月在我院行头颈部TOF MRA检查患者95例,其中43例并行头颈部CE MRA检查,另52例并行颈动脉分叉部双反转恢复T2WI血管壁黑血成像。统计同时行TOF MRA和CE MRA患者组中两种技术完成的图像中脑血管、颈内动脉虹吸段、颈动脉分叉部、椎动脉起始部等多个部位动脉血管狭窄数量,对两种技术诊断结果行Kappa一致性检验。统计同时行TOF MRA和DIR颈动脉分叉部血管壁黑血成像患者组中狭窄血管数量,对两者行χ2检验判断有无统计学差异。结果:行头颈部TOF MRA和CE MRA患者组,各部位诊断结果Kappa值分别为:大脑前动脉A1段0.710,大脑中动脉M1段0.823,大脑后动脉P2段0.672,颈内动脉虹吸段0.729,颈动脉分叉部0.634,椎动脉起始部0.707。行头颈部TOF MRA和颈动脉分叉部DIR T2WI黑血血管壁成像患者组,两者诊断结果χ2=1.11,P0.05,无统计学差异。结论:3D TOF MRA和CE MRA技术均可明确诊断绝大部分头颈部动脉血管狭窄病变,但也有各自的不足,颈动脉血管壁黑血成像可明确诊断有无粥样硬化斑块形成,是对头颈部MRA成像的有效补充,三者的合理应用及结合可以从多方面来诊断头颈部血管狭窄性病变,弥补相互间的不足。     

烟雾病的MRI、MRA诊断价值

 目的探讨MRI、MRA对烟雾病(Moyamoya病)的诊断价值.方法对11例Moyamoya病患者行MRI和MRA检查,MRI包括横轴位和矢状位T1WI、T2WI、FLAIR;MRA采用3D TOF法,3例行增强MRA.结果MRI表现为:(1)Moyamoya血管:双侧3例,单侧8例;(2)脑梗死和脑软化灶11例;(3)局部脑萎缩3例.MRA表现为3例双侧颈内动脉狭窄,双侧大脑中、前动脉闭塞,大脑后动脉形成异常血管网;6例右侧颈内动脉、大脑中动脉狭窄;2例左侧颈内动脉、大脑中动脉狭窄.结论MRI能良好的显示脑内病变,MRA能较完整的显示异常血管,MRI与MRA相结合可作为烟雾病诊断的首选检查方法.     

磁共振弥散成像与血管成像在短暂性脑缺血发作中的应用

目的 评价磁共振弥散成像(DWI)与血管成像(TOF-MRA、3DCE-MRA)对短暂性脑缺血发作(TIA)的应用价值.方法 对176例临床证实为TIA患者行MRI(FLAIR)、DWI、TOF-MRA及3DCE-MRA检查.结果 176例TIA患者中,48.9%病例DWI显示有超早期小血管梗塞灶,18.2%病例T2WI发现相应病灶.颅动脉检查中,TOF-MRA显示动脉狭窄及闭塞76例(43.2%),其中假阳性与过度评价20例;3DCE-MRA发现颅内动脉狭窄及闭塞69例(39.2%);两者均发现动脉瘤3例及动静脉畸形2例;颈部3DCE-MRA发现动脉狭窄及闭塞38例(21.6%).结论 DWI和MRA检查有助于TIA患者超早期小梗塞灶的发现及动脉病变的评估.     

头颈部血管闭塞性疾病的MRA与DSA对照研究

目的通过与DSA对照,探讨MRA在头颈部血管闭塞性疾病的应用价值与限度。方法回顾性分析头颈部血管检查的病例32例,均进行2D-TOFMRA和DSA检查,检查结果进行对照分析。结果32例经DSA检查8例为正常,余24例中病变血管共38支,其中轻度狭窄12支,中度狭窄8支,重度狭窄8支,闭塞10支;MRA正确诊断26支,总体准确率为约70%。椎动脉假阳性较高,达62.5%。结论MRA可以作为颈动脉和大脑动脉环闭塞性疾病的筛选方法,但不适宜应用于椎动脉。     

经颅彩色多普勒超声与MRA对颅内动脉狭窄的诊断价值比较

目的：比较经颅彩色多普勒超声（TCCD）与MRA对颅内动脉狭窄的诊断准确率。方法：回顾性分析60例（540条颅内动脉）颅内动脉狭窄患者的TCCD与MRA资料,并对比研究。结果：TCCD诊断颅内动脉狭窄148条,诊断敏感度及特异度分别为92.7%和90.1%。MRA诊断颅内动脉狭窄151条。结论：TCCD与MRA均能较准确地反映颅内动脉的狭窄情况,TCCD对诊断颅内动脉狭窄具有较高的敏感性和特异性,有重要的临床价值。     

症状性颅、颈部动脉狭窄在3.0T上的MRA与DSA比较研究

目的前瞻性分析3．0T应用SENSE技术的高分辨率对比增强容积扫描MRA（CEMRA）和3DTOFMRA在临床疑有颅、颈部动脉狭窄性病变患者中的应用价值。方法46例临床怀疑颅、颈部动脉狭窄的患者接受头颅MRI平扫、头颅3DTOFMRA和颈部CEMRA检查。动脉狭窄的程度与DSA检查结果进行相关性比较。结果MRA显示各段颅、颈部动脉狭窄的不同程度和DSA检查显著相关（Rs=0．97,P〈0．01）。以DSA结果为金标准,狭窄程度超过50％者MRA诊断灵敏度为100％,特异度为99．4％、准确率为99．4％。结论3．0T的3DTOFMRA和高分辨率CEMRA检查能可靠和有效地评价颅、颈部动脉狭窄性病变,可作为DSA术前必要的检查技术,或可替代传统DSA诊断性检查。     

非增强MRA诊断下肢动脉病变的应用研究

目的：探讨QISS非增强MRA技术诊断下肢动脉闭塞性病变的临床应用价值。方法：51例下肢动脉病变患者行双下肢QISS-MRA和CE-MRA扫描,评价两种检查方法的图像质量,并以CE—MRA为参照标准,计算QISSMRA诊断下肢动脉显著性狭窄（≥50％）的敏感度、特异度、阳性预测值、阴性预测值和诊断准确性,并以配对χ2检验分析两种检查方法对诊断下肢动脉显著性狭窄（≥50％）的差异有无统计学意义,两种检查方法的相关性采用kappa检验。结果：51例中48例成功行QISS-MRA检查,其中图像质量优、良、差者分别为40（78．43％）、8（15．69％）和3例（5．88％）。按血管节段计算,QISS-MRA诊断下肢动脉显著性狭窄的敏感度和特异度分别为90．15％和98．87％,阳性预测值和阴性预测值分别为96．75％和96．42％,总体符合率为95．91％。对于下肢动脉显著性狭窄的诊断,QISS-MRA与CE-MRA的差异无统计学意义（χ2=3．76,P〉0．05）,且两种检查方法具有极好的相关性（r值为0．950,P〈0．001）。结论：QISS-MRA检查成功率较高、图像质量良好并且诊断效果接近CE—MRA,对诊断下肢动脉闭塞性病变有一定的临床应用潜力。     

CTA与MRA诊断动脉瘤及评估动脉瘤破裂风险的比较

 目的 比较CT血管造影术(CT angiography,CTA)与磁共振血管造影(magnetic resonance angiography,MRA)诊断动脉瘤与动脉瘤破裂的风险评估价值。方法 48例高度怀疑为颅内动脉瘤患者随机分为两组,每组24例,记为Ⅰ组和Ⅱ组,其中Ⅰ组行CTA+DSA检查,Ⅱ组行MRA+DSA检查。比较CTA及MRA对颅内动脉瘤的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值及准确率。比较CTA及MRA对5 mm以上动脉瘤的诊断价值。结果 MRA诊断颅内动脉瘤的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值、准确率较CTA稍低,但二者差异无统计学意义。CTA与三维增强MR血管成像(3D CE-MRA)对5 mm以上动脉瘤的诊断能力相当,但与三维时间飞跃法MR血管成像(3D TOF MRA)相比,CTA与CE-MRA的诊断灵敏度、诊断特异性、阳性预测值、阴性预测值、准确率明显较高,差异有统计学意义(P<0.05);CTA能更清楚地显示瘤颈。结论 CTA和MRA可作为诊断动脉瘤与动脉瘤破裂的风险评估的首要手段,CTA诊断的准确率及三维形态高于MRA。     

TCD和CDFI联合检测对椎-基底动脉狭窄的诊断价值

目的将通过经颅多普勒超声（TCD）和彩色多普勒血流显像（CDFI）联合检测诊断的椎-基底动脉狭窄患者的检测资料进行分析,并与数字减影血管造影（DSA）做对比研究,客观评价二者对椎-基底动脉狭窄的诊断价值。方法经TCD、CDFI诊断的椎-基底动脉狭窄患者38例,均进一步行磁共振血管造影（MRA）、DSA检测,对比分析其检测结果。结果与DSA比较,TCD、CDFI对椎动脉的检测敏感性为83%,特异性为91%;TCD对基底动脉狭窄检测的敏感性为75%,特异性为93%。以DSA为标准,TCD对基底动脉近段、中段、远段的检出率分别为100%、50%和33%。以DSA为标准,TCD＋CDFI对椎-基底动脉狭窄的检出率为79%,MRA的检出率为96%,TCD、CDFI、MRA三者联合检出率为98%。结论①TCD、CDFI对椎-基底动脉狭窄的特异性较高,且无创、经济、方便,故可作为首选筛查手段。但因其敏感性不是很高,故当临床出现后循环神经缺失症状,而检测结果阴性时,可结合MRA检查;②TCD、CDFI、MRA三者联合对VBA狭窄有较好的准确性。     

3D-ASL在短暂性脑缺血发作中的诊断价值

目的 探讨MR三维动脉自旋标记(3 D-ASL)灌注成像在短暂性脑缺血发作(TIA)中的诊断价值.方法 对78例临床诊断为TIA的患者行MR常规扫描[(T1 WI、T2 WI、T2-FLAIR、扩散加权成像(DWI)]、磁共振血管成像(MRA)和3D-ASL扫描.根据扫描结果进行χ2检验并分析.结果 78例患者中,常规扫描显示信号异常0例(0%);MRA显示血管异常41例(52.6%);3 D-ASL显示灌注异常47例(60.2%);两者联合应用显示异常患者60例(76.9%),其中MRA阳性+ASL阳性29例;MRA阳性+ASL阴性12例;MRA阴性+ASL阳性19例;MRA阴性+ASL阴性18例.结论 3 D-ASL技术在TIA的诊断上优于MR常规序列,且方便易行,应该作为TIA诊断的常规扫描序列.3 D-ASL、MRA、DWI 3种检查方法各具优缺点,联合应用可以提高TIA的诊断准确率.     

3.0T时间飞跃法MRA诊断颅内动脉瘤-与DSA对照

目的评价3.0T时间飞跃法磁共振血管成像(3.0TTOFMRA)对颅内动脉瘤的诊断价值。方法对34例临床提示颅内动脉瘤患者前瞻性行3.0TTOFMRA及脑血管DSA检查。所有图像由3名医师分成2组在工作站上进行读片。第1组由2名高年资神经影像组医师分别独立阅读重建的最大密度投影(MIP)图像;第2组由1名高年资神经影像组医师同时阅读MIP和原始数据图像(sourceimage)。以DSA诊断结果作为标准,评价3.0TTOFMRA诊断颅内动脉瘤的灵敏度、特异度及正确率。结果DSA共检测20枚动脉瘤(19例),其中颈内动脉7例,前交通动脉5例,后交通动脉5例,大脑前、中动脉各1例。TOFMRA总体诊断灵敏度、特异度、正确率分别为94.8%、89.4%和91.4%。第2组的诊断有效性最高,两组间诊断阳性率差异无统计学意义(χ2=0.242,P>0.05和χ2=0.172,P>0.05)。结论3.0TTOFMRA作为一种快速、无创的影像检查方法,能够很好显示颅内动脉瘤。MIP结合Source图像可提高3.0TTOFMRA诊断的准确性。     

时间分辨随机轨道MR血管成像对周围动脉闭塞性疾病小腿动脉的成像研究

目的 评价3.0 T时间分辨随机轨道(TWIST)MRA提供的小腿动脉血流动力学指标和形态学诊断的价值.方法 40例临床证实或怀疑周围动脉闭塞性疾病(PAOD)的患者接受小腿段TWIST MRA及全下肢对比增强MRA(CE-MRA)检查.由TWIST MRA确定双侧腘动脉开始显示时间,双侧腘动脉开始显影时间差,小腿动脉通过时间和小腿动脉平均达峰时间.分析小腿动脉平均达峰时间与踝肱指数(ABI)的关系.评价小腿各段动脉在TWIST MRA及CE-MRA的图像显示情况,包括血管显示度、静脉重叠情况和动脉狭窄程度.组间比较采用t检验或校正t检验,动脉平均达峰时间与ABI的关系采用Pearson分析.对16例患者,以DSA为金标准,分别评价TWIST MRA、CE-MRA诊断各级动脉狭窄的敏感性和特异性.结果 (1)纳入评价的79侧下肢腘动脉开始显影时间为(30.7±7.6)s,双侧腘动脉开始显影时间差为(2.1±2.5)s,小腿动脉通过时间为(35.6±16.9)s,小腿动脉平均达峰时间为(52.6±17.6)s.(2)24例接受ABI检查的患者共计得到48个ABI指数(均值为0.62±0.23),与小腿动脉平均达峰时间呈正相关(r＝0.627,P＜0.01).(3)851段参与评价的血管中,TWIST MRA显影动脉节段849段,显示度评分为(2.83±0.48)分;CE-MRA显影动脉节段845段,显示度评分为(2.78±0.43)分(P＞0.05).(4)以DSA共显示的194段动脉节段为金标准,TWIST MRA显示正常及轻度狭窄的敏感性为96.7%(118/122)、特异性为100.0% (72/72),显示明显狭窄的敏感性为94.1%(32/34)、特异性为96.2% (154/160),显示闭塞的敏感性为94.7%(36/38)、特异性为98.7% (154/156);CE-MRA显示正常及轻度狭窄的敏感性为95.9%(117/122)、特异性为100% (72/72),显示明显狭窄的敏感性为91.2%(31/34)、特异性为95.6% (153/160),显示闭塞的敏感性为94.7%(36/38)、特异性为98.1%(153/156).结论 TWIST MRA操作简便,无静脉污染,一次检查不仅能准确显示小腿动脉病变,而且能提供反映疾病程度的功能学信息.

Abstract：

Objective To explore the value of time-resolved angiography with interleaved stochastic trajectories (TWIST)in providing hemodynamic indices and morphological imaging of calf arteries in patients with peripheral arterial occlusive disease(PAOD) with 3.0 T MR scanner. Methods Forty patients with confirmed or suspected PAOD underwent TWIST MRA for the calf arteries and conventional contrast-enhanced MRA(CE-MRA) for the whole lower peripheral arteries. TWIST MRA data were used to determine the bolus arriving time of the popliteal artery, the time difference of the bolus arrival in the popliteal artery between the two legs, calf artery transit time, and the mean peak enhancement time of calf arteries. The mean value of peak enhancement time of calf arteries was correlated with ankle-brachial index(ABI). The calf arteries were divided into 13 segments. The visible score of arterial segment was recorded, and the degree of arterial stenosis was graded too. In 16 patients, DSA was used as the gold standard to evaluate the sensitivity and specificity of TWIST MRA and CE-MRA. Results The bolus arriving time of the popliteal artery was (0.7±7.6) s the time difference of the bolus arrival in the popliteal artery between the two legs was (2.1±2.5) s, the calf artery transit time was (35.6±16.9) s, the mean value of peak enhancement time of calf arteries was (52.6±17.6) s. ABI was acquired from 24 patients and 48 legs, which correlated well with the mean value of peak enhancement time in calf arteries (r＝0.627,P＜0.01). The mean visible score was (2.83±0.48) of TWIST MRA images and (2.78±0.43) of CE-MRA images. There was no significant difference between them (P＞0.05). On CE-MRA, there were 38 legs with varying degrees of early venous enhancement; in contrast, there was no venous contamination on TWIST MRA. The sensitivity and specificity of TWIST MRA were 96.7% (118/122) and 100.0% (72/72) in showing normal artery and mild stenosis, 94.1% (32/34) and 96.2% (154/160) in showing severe stenosis, and 94.7% (36/38) and 98.7% (154/156) in showing occlusion. The sensitivity and specificity of CE-MRA were 95.9% (117/122) and 100.0% (72/72) in showing normal artery and mild stenosis, 91.2% (31/34) and 95.6% (153/160) in showing severe stenosis, and 94.7% (36/38) and 98.1% (153/156) in showing occlusion. Conclusion TWIST MRA is a preferable choice for calf arterial occlusive disease, which provided nice morphological images and useful hemodynamic indices with simple operation.     

Comparison of digital subtraction angiography with gadolinium-enhanced magnetic resonance angiography in the diagnosis of renal artery stenosis

Renal artery stenosis (RAS) is a treatable cause of hypertension and renal failure for which no ideal screening technique is currently available. We evaluated the use of dynamic gadolinium-enhanced magnetic resonance angiography (MRA) for the diagnosis of RAS. Sixty-two patients with secondary hypertension were enrolled in the study. All patients had conventional renal angiography and gadolinium enhanced MRA. The sequence used was a 3D FMP SPGR sequence with the following parameters (TR: 26 ms, TE: 6.9 ms, flip angle 40 °, field of view 36 × 36 cm, matrix 246 × 256, 1 excitation). Gadolinium 0.3 mmol/kg was administered and 60 1.5-mm-thick partitions were obtained over a duration of 3.5 min. The MRA images were then compared with conventional digital subtraction angiography (DSA) images. Conventional DSA demonstrated 138 renal arteries, whereas gadolinium-enhanced MRA demonstrated 129 (93 %). Twenty-one renal artery stenoses and four occluded arteries were seen at conventional DSA. Gadolinium-enhanced MRA had a sensitivity of 88 %, specificity of 98 %, accuracy of 96 %, positive predictive value of 92 % and negative predictive value of 97 % when compared with conventional DSA. Gadolinium-enhanced MRA is an accurate technique for identifying patients with RAS. It is less sensitive in picking up accessory renal arteries. Received: 17 March 1998; Revision received: 30 June 1998; Accepted: 28 August 1998     

3D nongadolinium-enhanced ECG-gated MRA of the distal lower extremities: preliminary clinical experience

PURPOSE: To report our initial experience implementing a noncontrast-enhanced electrocardiograph (ECG) gated fast spin echo magnetic resonance angiography (MRA) technique for assessment of the calf arteries. MATERIALS AND METHODS: Noncontrast MRA images of 36 clinical patients examined over a 6-month period were evaluated by two radiologists for length and degree of stenosis of arterial segments. Diagnostic confidence in the technique was also recorded. The reference standard was a consensus reading by both radiologists using the noncontrast technique combined with two gadolinium-enhanced techniques: bolus-chase and time-resolved imaging. RESULTS: For stenosis evaluation the noncontrast technique demonstrated accuracy 79.4% (1083/1364), sensitivity 85.4% (437/512), and specificity 75.8% (646/852). The sequence demonstrated high negative predictive value (92.3%, 646/700). The technique had serious artifacts leading to poor diagnostic confidence in 17 patients (47.2%). These included motion (n = 7) and artifacts specific to the sequence, including inaccurate trigger delays (n = 5), linear artifact (n = 7), and vessel blurring (n = 5). When only patients in whom there was satisfactory diagnostic confidence were considered, accuracy, sensitivity, and negative predictive value were 92.2% (661/717), 92.4% (158/171), and 97.5% (503/516), respectively. CONCLUSION: Our results indicate that when technically successful, noncontrast-enhanced MRA using ECG-gated fast spin echo can provide accurate imaging of the calf and pedal arteries. However, further development and optimization are needed to improve the robustness of the technique.